In various types of coordinate measuring machines, the points on the surface of a workpiece may be sensed with a probe. In one type of probe, the workpiece is directly measured by touching a mechanical contact of the probe to various points along the workpiece surface. In some cases, the mechanical contact is a ball. Certain coordinate measuring machines use both optical and mechanical measuring sensors. Such devices are described in U.S. Pat. Nos. 4,908,951 and 5,825,666, which are hereby incorporated by reference in their entirety. Auto changing racks are also disclosed for holding multiple probes, a probe holder, and lenses for selective mounting on a camera, and the like.
Related to auto changing racks, frequently interchangeable measuring probes are attached to coordinate measuring machines at an auto exchange joint connection included in various “probe heads”. At present, Renishaw probes heads are the most commonly used for certain applications in the industry. These probes heads are manufactured by Renishaw-Metrology Limited in Gloucestershire, United Kingdom. While Renishaw™ type probe head systems are the most commonly used in the industry, certain technologies are not easily incorporated into Renishaw-type systems. Furthermore, attempts to upgrade an existing Renishaw-type probe head system to one with more advanced capabilities can entail significant costs and/or inconvenience. For example, certain technologies adapted to a Renishaw-type probe head system may lack desirable features, lack a desirable level of controllability, and/or lack the capacity for being automatically interchangeable with other types of probes that may be interfaced to the Renishaw-type probe head system. One particular issue with regard to using Renishaw-type probe head systems, or similar systems, is that the existing data and control connections between the machines and the probes consist of a limited number of wired connections. This effectively forms a “bottleneck” which makes it difficult to add additional technologies and/or features to a probe that is to be mounted and/or exchanged using the probe head system. In particular, existing chromatic range sensors have not typically been automatically attachable and/or interchangeable using a Renishaw-type probe head system or the like.
One issue for measuring probes is the danger of a collision with a workpiece. During measurement operations, a measuring probe may be moved by a coordinate measuring machine to different physical locations for measuring a workpiece surface. During such movements, a collision may accidentally occur between the measuring probe and the workpiece or other physical object. Such collisions may cause damage to the probe, the coordinate measuring machine, and/or the workpiece. It would be desirable if a chromatic range sensor probe could provide a capability for sensing a detachment condition of a portion of its optical pen in the event of a collision, for example while utilizing a Renishaw-type probe head system or the like, and/or optical pen components that would be automatically attachable and/or interchangeable to an optical pen base member while on a coordinate measuring machine, for example, by using an auto changing rack.